Categorical learning in choice-reaction tasks

Judy Burgess "Addie" Dutta, Purdue University

Abstract

Much research has been concerned with the basis for improvement in choice-reaction tasks. One conclusion from this research is that it is response-selection processes that are most affected by practice. Questions remain as to how response-selection processes are affected and as to the type of information on which they operate. The present study evaluates two hypotheses regarding the development of specialized response-selection processes: the creation of ad hoc category nodes and the learning of stimulus and response set features and relationships. The ad hoc category hypothesis was proposed by Pashler and Baylis (1991) to account for the finding that assigning new stimuli to already practiced responses disrupts responding to the stimuli that originally were practiced. They suggested that ad hoc category nodes are created to encompass preexperimentally unrelated groups of stimuli and their assigned responses. When new stimuli are introduced, new ad hoc categories must be created. The alternative hypothesis, that the structural mapping of the stimulus and response sets is learned, was proposed on the basis of stimulus-response compatibility studies showing that the relation of stimuli to responses is an important determinant of performance in choice-reaction tasks both early and late in practice. The results of the experiments suggest that categorization of stimuli occurs only when the stimuli contain features that distinguish between subsets of stimuli. Response-set structure alone does not appear to provide a basis for grouping stimuli into subsets. Accounts of learning in choice-reaction tasks with many-to-one mappings of noncategorizable stimulus sets will need to consider the relation of individual stimulus-response pairs to all other stimuli and responses, regardless of particulars of the response assignments.

Degree

Ph.D.

Advisors

Proctor, Purdue University.

Subject Area

Psychology|Experiments

COinS